JPH0454934B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a silver halide photographic material, and more particularly to a silver halide photographic material with improved sensitivity and fog. Increasing the sensitivity without reducing the quality of photographic images is a persistent and continuing desire of users of photographic materials. In response to this, several sensitization techniques have been developed in the photographic industry as a result of various studies. Among these, it is known that a thioether compound is used as a sensitizer in the production of silver halide emulsions as a highly effective and highly practical technique. For example, US Patent No. 2521926, US Patent No. 3021215,
Same No. 3038805, No. 3506443, No. 3057724, Same No.
No. 3062646, No. 3574709, No. 3622329, No.
No. 3,625,697 and other publications propose a technique for increasing the photographic sensitivity of an emulsion by making a thioether compound present during chemical ripening during emulsion production or immediately before coating. However, although these thioethers have very effective sensitizing properties, there are still many unresolved technical problems in their use in products as photographic materials. Among these, a major and fatal problem is the instability of the effect of adding thioether. That is, changes in the drying conditions of a coated emulsion containing a thioether, changes in additives in the emulsion,
In addition, changes in conditions such as the development method of the finished photosensitive material may cause a significant increase in fog, and even if the purpose of the sensitizing effect is achieved, the increased fog reduces the value of the product. Decrease. Conversely, even if no fogging occurs, the sensitizing effect may disappear completely due to changes in the conditions described above.
In order to suppress fog, we refrain from chemical aging,
Alternatively, measures such as adding an antifoggant are taken, but this significantly impairs the sensitization, and the use of thioether becomes meaningless.
Furthermore, if you try to guarantee low fog density and high sensitivity through development processing conditions, you will have to develop and specify the optimal processing conditions for each new product development, which is not necessarily a great benefit for both users and manufacturers. do not have. A first object of the present invention is to provide a silver halide photographic material that stably and significantly increases sensitivity without increasing fog. A second object of the present invention is to provide a silver halide photographic material with improved sensitivity deterioration over time. A third object of the present invention is to provide a silver halide photographic material with increased maximum density and contrast. As a result of extensive exploration research, the present inventors have achieved the above object by creating a silver halide photographic light-sensitive material characterized by containing at least one compound represented by the following general formula (). I discovered that. General formula () In the formula, R ₁ , R ₃ , R ₄ and R ₆ represent lower alkyl groups having 1 to 5 carbon atoms, and R ₂ and R ₅ represent lower alkyl groups having 1 to 5 carbon atoms.
Represents up to 15 alkyl, aryl, aralkyl, hydroxyalkyl or heterocyclic groups. A, A' and B are alkylene groups, arylene groups,
It represents an aralkylene group or a fluoroalkylene group, which may be the same or different. ) The number of carbon atoms in R ₁ , R ₃ , R ₄ and R ₆ above is 1 or more
Examples of the lower alkyl group of 5 include methyl, ethyl, propyl, butyl, and pentyl groups. Examples of the alkyl group having 1 to 15 carbon atoms in R ₂ and R ₅ include CH ₃ , C ₁₁ H ₂₃ , C ₁₅ H ₃₁ or CCl ₃ group, and examples of the aryl group include phenyl group and p-chlorophenyl group. Examples include. Examples of aralkyl groups include benzyl group, phenethyl group,

[Formula] etc., hydroxyalkyl Examples of the group include hydroxyethyl group,

[Formula] group,

【formula】 basis,

[Formula] Groups, etc. can be mentioned. Examples of the heterocyclic group include a pyrrolyl group and a piperidyl group. Examples of alkylene groups in A, A' and B include ethylene group, propylene group, butylene group, or Examples of the arylene group include a phenylene group. Further, as the aralkylene group, for example,

[Formula] group,

Examples include [Formula] groups. Examples of the fluoroalkylene group include _-CF2
A _CF2- group may be mentioned. Specific examples of the compounds related to the present invention are listed below, but the present invention is of course not limited to these uses. The compound according to the invention can be contained in the emulsion layer, other layers adjacent to the emulsion layer (for example, a protective layer), or both. The amount added is preferably 10 mg to 1 g, more preferably 20 mg to 300 mg, per mole of silver halide used in the silver halide photographic material of the present invention. It may be added at any time during or before coating the silver halide emulsion, but if the layer to be contained is an emulsion layer, it is preferably added after chemical ripening or during coating. Various silver halides can be used in the silver halide emulsion layer according to the present invention. Examples include silver chloride, silver bromide, silver chlorobromide, silver iodobromide, and silver chloroiodobromide. Crystal form of silver halide grains,
There are no limitations on the crystal structure, grain size, grain size distribution, etc. For example, the crystal shape may be cubic, octahedral, or tetradecahedral, normal crystal, or twin crystal. Further, it may be an emulsion with a wide particle distribution or a monodisperse emulsion. The crystal structure may be uniform, the inside and outside may have different compositions, it may have a layered structure, or silver halides of different compositions may be joined by epitaxial bonding. good. Further, the latent image may be formed mainly on the surface or inside. The silver halide emulsion can be sensitized using conventional chemical sensitization, that is, sulfur sensitization using sodium thiosulfate, allylthiocarbamide, thiourea, allyl thiocyanate, etc., and noble metal sensitization using platinum chloride. Potassium acid, ammonium palladate chloride or salts of noble metals such as ruthenium, rhodium, iridium, platinium, etc. can also be used. Sensitization can also be achieved by using these noble metal salts in combination with a sulfur sensitizer, and further with rhodanammonium as an auxiliary agent. Furthermore, selenium sensitization methods include methods using selenourea, N-N dimethylselenourea, N-dimethylselenourea, etc., and reduction sensitization methods include methods using tin salts, methods using polyamines, and quaternary ammonium salts. Sensitization can also be achieved depending on the method used. Furthermore, sensitization methods using polyalkylene oxide compounds and sensitization methods using thioethers can also be used. The silver halide emulsion according to the present invention can be imparted with color sensitivity in a desired wavelength range by using a sensitizing dye. Various sensitizing dyes can be used, and one or two sensitizing dyes may be used.
More than one species can be used in combination. Dyes that can be advantageously used in the present invention include methine dyes and styryl dyes such as cyanine, hemicyanine, rhodacyanine, merocyanine, oxonol, and hemioxonol. In particular, US Pat.
Specifications of each issue, Special Publication No. 43-13821, No. 44-32753
No. 46-18106, No. 47-8741, No. 47-37443
The sensitizing dyes described in each publication and JP-A-48-89722 are effective in the present invention. The main specific pigment is 3,3'-di-
(3-sulfopropyl)selenacarbocyanine hydroxide, 5,5'-diphenyl-3,3'-di-
(3-Sulfopropyl)oxacyanine hydroxide, 5,5'-diphenyl-3,3'-di-(3-
sulfopropyl)oxacarbocyanine hydroxide, 3-allyl-5-[1-methyl-2(1H)
Piperidylidene] rhodanine, 3-(4-sulfobutyl)-1'-ethyl-5'-methylselenium-2'-cyanine hydroxide, 1-hydroxyethyl-3
-phenyl-5-[3(3-sulfopropyl)-2
-Benzoxazolinidene]ethylidene-2-thiohydantoin sodium salt, 5,5'-dichloro-9-ethyl-3,3'-di-(3-sulfopropyl)oxacarbocyanine hydroxide, 5,
5'-diphenyl-9-ethyl-3,3'-di(3-
sulfopropyl)oxacarbocyanine hydroxide, 5,5',6,6'-tetrachloro-1,1'-
Diethyl-3,3'-di-(4-sulfobutyl)benzimidazolocarbocyanine hydroxide sodium salt, 5,5'-di-(butoxycarbonyl)-
1,1'-diethyl-3,3'-di-(3-sulfopropyl)benzimidazolocarbocyanine hydroxide, 5,5'-dichloro-1,3'-diethyl-
6'-methyl-3-(4-sulfobutyl)benzimidazoloxacarbocyanine hydroxide,
5,5'-dichloro-9-ethyl-3,3'-(dicarboxyethyl)-thiacarbocyanine hydroxide, 5,5'-dichloro-3,9-diethyl-
3'-(3-sulfopropyl)-thiacarbocyanine hydroxide, 5,5'-dimethyl-9-ethyl-
3,3'-di-(3-sulfopropyl)thiacardi(3-sulfopropyl)4,5,4',5'-dibenzothiacarbocyanine hydroxide, 9-ethyl-3,3'-di(3- sulfopropyl)-5,6,
Examples include 5',6'-dibenzoxacarbocyanine hydroxide. The silver halide emulsion according to the present invention is used as a stabilizer and a fog suppressant, for example, in the specifications of US Pat. No. 2,444,607, US Pat. No. 2,716,062, US Pat. No. 2058626,
Specifications of No. 211841, Special Publication No. 43-4133, No. 39
-2825 publications, JP-A-50-22626, JP-A-50-
You may apply the method described in each publication such as No. 25218,
Particularly preferred compounds include 4-hydroxy-
6-methyl-1,3,3a,7-tetrazaindene, 4-hydroxy-cyclopentano[f]-1,
3,3a,7-tetrazaindene or gallic acid esters (e.g. isoamyl gallate, dodecyl gallate, propyl gallate, sodium gallate), mercabutanes (1-phenyl-5-mercabutotetrazole, 2-mercabutane) Examples include benzothiazole) benzotriazoles (5-brombenzotriazole, 4-methylbenzotriazole), benzimidazoles (6-nitrobenzimidazole), and resorcinols. The silver halide photographic material of the present invention has photographic hardeners commonly used in its coating solution, such as aldehyde-based, aziridine-based, isoxazole-based, epoxy-based, vinyl sulfone-based, acryloyl-based, carbodiimide-based, maleimide-based, Hardening agents such as acetylene type, methanesulfonic acid ester type, triazine type, and polymer type can be used. In addition, as a thickening agent, for example, U.S. Pat.
3767410, Belgian Patent No. 558143,
Polyols, latexes, etc. may be used as gelatin plasticizers. Further, as a matting agent, those described in British Patent No. 1221980 and the like can be used. In the components of the silver halide photographic light-sensitive material according to the present invention, for example, saponin or sulfosuccinic acid type surfactants, and anionic surfactants can be used as coating aids. The binder applicable to the present invention includes gelatin, and gelatin derivatives such as phenylcarbamyl gelatin, acylated gelatin, phthalated gelatin, or ethylene groups such as styrene acrylate, acrylic ester, methacrylic acid, and methacrylic ester. There are gelatin graft-polymerized polymerizable monomers with These hydrophilic colloids can be used in layers with or without silver halide, such as protective layers, intermediate layers, etc.
It may be used in filter layers or other photographic material components. When the present invention is applied to color photosensitive materials, various couplers can be used. For example, an open-chain ketomethylene coupler can be used as a yellow coupler, and a pyrazolone type, pyrazolotriazole type, or pyrazolone type coupler can be used as a magenta coupler. Examples include compounds such as nobenzimidazole and imidazolone. In addition, cyan couplers include phenolic,
In addition to the naphthol type, colored magenta couplers, colored cyan couplers, development inhibitor-releasing couplers, development inhibitor-releasing substances, Weis couplers, competing couplers, etc. may be used. Furthermore, tinuvins may be used as ultraviolet absorbers, and optical brighteners, image stabilizers, antioxidants, lubricants, sequestering agents, emulsifying dispersants,
etc. can be used. The silver halide photosensitive material of the present invention has functional auxiliary layers such as a protective layer, an intermediate layer, a filter layer, an antihalation layer, a subbing layer, an irradiation prevention layer, and a backing layer as layers other than the halogenated emulsion layer. Supports that can be used include baryta paper, polyethylene-coated paper, polypropylene synthetic paper, glass plates, cellulose acetate, cellulose nitrate, polyvinyl acetal, polypropylene, polyester films such as polyethylene terephthalate, polyamide films, and polycarbonate films. , styrene film, etc., and these supports are appropriately selected depending on the intended use of the silver halide photographic material. Next, the developer used in the present invention is of a commonly used type, and the developer includes hydroquinone,
N-methyl-p-aminophenol, 1-phenyl-3-pyrazolidone, paraphenylenediamines, etc. are used alone or in combination. The developer also contains alkaline agents such as sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide,
Preservatives such as sodium metaborate and alkanolamine; preservatives such as sodium sulfite, potassium sulfite, sodium bisulfite, potassium birosulfite, formaldehyde, and sodium bisulfite adduct; development fog inhibitors such as 5-nitrobenzimidazole and 5-methyl; Benzotriazole, 8-nitrobenzotriazole, 1-
Azoles such as phenyl-5-mercaptotetrazole can be used as appropriate. Further, as a hardening agent, an aldehyde compound known for hardening gelatin and other polymers can be used. Preferred aldehydes include dialdehyde compounds such as glutaraldehyde, maleic dialdehyde, and bisulfites thereof. Furthermore, the developer contains antioxidants such as 3-6-dihydroxypyridazine, polyamines, polyalkylene oxide compounds, alkylene glycols, organic solvents such as methyl alcohol, dimethylformamide, cellosolve, benzyl alcohol, and ascorbin. Acids etc. are used as necessary. Additionally, chelating agents, PH adjusting agents, buffering agents, etc. can also be used. The development time depends on the type of developer, processing temperature,
Although it varies depending on the photosensitive material used, the appropriate time is usually about 5 minutes or longer, or less than 1 minute and 5 seconds, and the development process can be carried out using a rapid automatic device using a vat type or a roller transfer type. Furthermore, the silver halide photographic material of the present invention includes:
For example, in the case of black and white negative photosensitive materials, development → fixing →
Water washing→drying, in the case of color negative photosensitive materials, color development→water washing→bleaching→water washing→fixing→water washing→stabilization, etc., depending on the type of photosensitive material to which it is applied.
Various processing steps can be taken. The silver halide photographic material of the present invention includes various types of silver halide photographic materials. For example, any material such as general black and white photosensitive materials, X-ray photosensitive materials, color photosensitive materials, printing photosensitive materials, copying photosensitive materials, diffusion transfer method photosensitive materials, silver dye bleaching method photosensitive materials, special photosensitive materials, etc. Although the present invention can be effectively applied to black and white photosensitive materials, the effect is particularly remarkable. The present invention will be explained in more detail below using specific examples, but the embodiments of the present invention are not limited to these. Example 1 Gelatin silver iodobromide cubic emulsion chemically sensitized using sodium thiosulfate and sodium chloroaurate (silver iodide content 2 mol% average grain size 1.2μ) 4 to 1 kg
-Hydroxy-6-methyl-1,3,3a,7-
10ml of 1% aqueous solution of tetrazaindene, saponin
30 ml of a 10% aqueous solution and 3 ml of a 3% aqueous formalin solution were added. (This emulsion contains 80 g of gelatin per mole of silver halide.) This emulsion is divided into parts, the compounds shown in Table 1 below are added, and a protective layer is coated so that the amount of silver coated is 7 g/ ^m2 . A sample was prepared by coating the same material on a polyethylene terephthalate blue colored support. These samples were exposed to white light using a KS-1 type sensitometer (manufactured by Konishi Roku Photo Industry Co., Ltd.) based on the JIS method, then developed in a tank, and after drying, the density was measured and the density was measured according to the usual sensitometric method.
Fog (F), specific sensitivity (RS), contrast (γ), and maximum density (Dmax) were measured. The developer used had the following composition () and the processing conditions were as follows:
20℃ for 4 minutes and 30 seconds. Composition of developer () Sodium sulfite 70g Hydroquinone 10g Sodium carbonate monohydrate 30g 1-phenyl-3-pyrazolidone 0.35g Brompotash 4g Make 1 with water. The results are shown in Table 1.

【table】

[Table] The amount added is the amount per mole of silver halide, and RS is 100 based on the sample to which no compound related to the present invention is added. Further, γ is expressed as tanθ, which is the angle θ formed with the horizontal axis of the slope of the straight line portion between densities 1.0 and 2.0 on the emulsion characteristic curve generally used in the photographic industry. As is clear from these results, by adding the compound according to the present invention, sensitivity is increased without increasing fog, and contrast and maximum density are also improved. Example 2 Using an emulsion prepared in the same manner as in Example 1 and a gelatin solution for a protective layer prepared by adding a usual coating aid, compounds related to the present invention and compounds other than the present invention shown below were prepared. Samples were prepared by adding compounds (A), (B), and (C) to the emulsion layer or protective layer, respectively. The coating amount was 7 g/m ² in terms of silver for the emulsion layer and 1.5 g/m ² in terms of gelatin for the protective layer. The coated sample was left under conditions of a temperature of 23°C and a relative temperature of 55%, and after 1 day, 15 days, and 60 days, it was exposed in the same manner as in Example 1, and then developed with a developer (). The emulsion properties were measured. The results are shown in Table 2. Symbols for photographic characteristics have the same meanings as in Example 1.

【table】

[Table] Samples to which the compound used in the present invention was added are compounds
Compared to samples containing (A), (B) or compound (C),
It can be seen that it has an excellent effect on improving contrast and maximum density, and also shows very little change over time. Furthermore, it can be seen that the compound used in the present invention produces similar effects when added not only to the emulsion layer but also to the protective layer.

Claims (1)

[Scope of Claims] 1. A silver halide photographic material containing at least one compound represented by the following general formula (). General formula () (In the formula, R ₁ , R ₃ , R ₄ and R ₆ represent lower alkyl groups having 1 to 5 carbon atoms, and R ₂ and R ₅ represent alkyl groups, aryl groups, and aralkyl groups having 1 to 15 carbon atoms. , represents a hydroxyalkyl group or a heterocyclic group. A, A' and B are an alkylene group, an arylene group,
It represents an aralkylene group or a fluoroalkylene group, and these may be the same or different. )